(a) Field of the Invention
The present invention relates to a plasma display panel (PDP), and more particularly, to a PDP that optimizes a structure of barrier ribs according to characteristics of red, green, and blue phosphors to improve the efficiency of phosphors of discharge cells and make discharge characteristics uniform.
(b) Description of the Related Art
A PDP is a display device that uses vacuum ultraviolet rays generated by gas discharge in discharge cells to excite phosphors, thereby realizing the display of images. With its ability to realize high-resolution images, the PDP is emerging as one of the most popular flat panel display configurations used for wall-mounted televisions and other similar large-screen applications. The different types of PDPs include the AC-PDP, DC-PDP, and the hybrid PDP. The AC-PDP utilizing a triode surface discharge structure is becoming the most common configuration.
In the AC-PDP with a triode surface discharge structure, address electrodes, barrier ribs, and phosphor layers are formed on a rear substrate corresponding to each discharge cell. Discharge sustain electrodes comprised of scanning electrodes and display electrodes are formed on a front substrate. A dielectric layer is formed covering the address electrodes on the rear substrate, and, similarly, a dielectric layer is formed covering the discharge sustain electrodes on the front substrate. Also, discharge gas (typically an Ne—Xe compound gas) is filled in the discharge cells.
Using the above structure, an address voltage is applied between an address electrode and a scanning electrode to select a discharge cell. Next, a discharge sustain voltage of 150-200V is applied between the display electrode and the scanning electrode of the selected discharge cell such that discharge gas effects plasma discharge, and vacuum ultraviolet rays having wavelengths of 147 nm, 150 nm, and 173 nm are emitted from the excited Xe atoms made during plasma discharge. The vacuum ultraviolet rays excite phosphors so that they glow (i.e., emit visible light) and thereby enable color display.
In the PDP operating in this manner, various steps are involved between applying power to a drive circuit to visible light passing through the front substrate for viewing by a user. Significant loss occurs in this process.
Illumination efficiency of the PDP may be described as the combination of a circuit efficiency that is a factor of circuit loss, discharge efficiency when converting discharge power to ultraviolet rays, an ultraviolet usage rate when ultraviolet rays are converted to effective ultraviolet rays, and a visible light usage rate when visible light is converted into display light.
Accordingly, when designing and manufacturing the PDP, great effort is put forth into ways to minimize loss during the various steps of operation. Except for circuit efficiency, all efficiencies in the various steps of operation depend primarily on the internal structure and material characteristics of the PDP, and, in particular, discharge cell structure, discharge gas, and phosphor material characteristics. Research, therefore, is concentrated in these areas.
Phosphors used in PDPs are excited at a lower energy level than phosphors used in cathode ray tubes. Therefore, there is a limited selection of phosphors that may be used in the PDP. Phosphors typically used in PDPs have different illumination efficiencies depending on color (i.e., depending on whether red, green, or blue phosphors). Stated differently, there are significant differences in brightness of phosphors used in PDPs according to color. This results in different phosphor efficiencies and discharge characteristics for the different discharge cells, as well as difficulties in controlling white balance and color temperature.